I don't know why so many had problems with 13T cog skip while having a GS
rear.
We often took the unit apart and advanced the spring tension.
We also looked at the chain dimension height.
If the chain was too wide top to bottom, and the cog was cut low, the chain
would hit the body and that would make it skip.
Cogs varied a little in production.
It was easy to determine because the chain roller plate would mark the body
and one could see that the chain wouldn't then seat into the tooth, riding
high in effect and thus skipping.
It could also be a worn cog and/or "stretched chain".
Remember that the pro's also used these cogs, and I don't think they would
have enjoyed staccato style pedaling.
We probably would have seen plenty bikes being pitched thru the air by the
riders and some very wild sprints.
Ted Ernst
Palos Verdes Estates
CA USA
<classicrendezvous@bikelist.org> Sent: Thursday, June 03, 2010 5:49 PM Subject: Re: [CR] My Most Recent Cinelli Projects
> As Mark observed, John you've done a lovely job with these two Cinellis. I
> wonder if I might be allowed a couple of Q. about the beautiful '63:
> --> Your Cinelli has a GS rear and Record front. I remember buying my
> first good road bike in '63, in DC. An Avanti, which came with a Gran
> Sport front. As part of the deal, the owner later sent me the Record
> front, which was already available. But memory suggests that my Avanti
> also came with a GS rear, because it wouldn't handle the 13th rear w/o
> skipping. Were these mixed pairs (GS/Record) common for a while?
> --> I've put BiValents on my 71 Cinelli (which will be at Cirque). I
> wasn't aware that they date back to '63, and wonder if they weren't a
> later upgrade by the owner. I'd keep 'em on, whether or not original, as
> part of the history of the bike, but do wonder if anyone remembers when
> they came out.
>
> Thanks, and really nice jobs!
>
> harvey sachs
> mcLean va
> +++++++++++++++++++++++++++++++++++
>
> Mark Bulgier wrote:
> John,
>
> Those are two of the nicest bikes I've seen in a while. The older black
> one really floats my boat, especially those handlebars with the
> integrated brake levers.
>
> Isn't the rear derailleur cage supposed be the other way though? I mean
> the pulley that's down should be up. Or maybe it works better set up
> 'wrong"? I'm certainly no expert on those.
>
> Compare
> http://www.velostuf.com/
> to
> http://velobase.com/
> F1EC5E284D91&Enum=108&AbsPos=2018
> (http://tinyurl.com/Simplex-tdf)